Simple d-glucosamine-based phosphine-imine and phosphine-amine ligands in Pd-catalyzed asymmetric allylic alkylations

Article abstract of DOI:10.1016/j.tetlet.2008.09.039

A new family of phosphine-imine and phosphine-amine ligands based on d-glucosamine were synthesized in order to probe previous asymmetric allylic alkylation results with those of disaccharide ligands of the same class. In most cases, good-to-excellent activities and enantioselectivies were observed with these ligands with ee's reaching up to 87% in the Pd-catalyzed allylic alkylation reaction of racemic (E)-1,3-diphenyl-2-propenyl acetate with dimethyl malonate as the nucleophile.

Full text of DOI:10.1016/j.tetlet.2008.09.039

Tetrahedron Letters 49 (2008) 6635–6638
Contents lists available at ScienceDirect
Tetrahedron Letters
journal homepage: www.elsevier.com/locate/tetlet
Simple D-glucosamine-based phosphine-imine and phosphine-amine
ligands in Pd-catalyzed asymmetric allylic alkylations
Katarzyna Glegoła a, Sine A. Johannesen b, Laura Thim b, Catherine Goux-Henry a,
a,
Troels Skrydstrup b, , Eric Framery
*
*
a Université de Lyon, F-69622, Lyon, France, Université Lyon 1, Villeurbanne, CNRS, UMR5246, ICBMS Equipe Synthèse Asymétrique, France
b Center for Insoluble Protein Structures, Department of Chemistry and Interdisciplinary Nanoscience Center, University of Aarhus, Langelandsgade 140, 8000 Aarhus C, Denmark
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 2 July 2008
Revised 3 September 2008
Accepted 5 September 2008
Available online 11 September 2008
A new family of phosphine-imine and phosphine-amine ligands based on D-glucosamine were synthe-
sized in order to probe previous asymmetric allylic alkylation results with those of disaccharide ligands
of the same class. In most cases, good-to-excellent activities and enantioselectivies were observed with
these ligands with ee’s reaching up to 87% in the Pd-catalyzed allylic alkylation reaction of racemic (E)-
1,3-diphenyl-2-propenyl acetate with dimethyl malonate as the nucleophile.
Ó 2008 Elsevier Ltd. All rights reserved.
Keywords:
Phosphine-imine
Phosphine-amine
D-Glucosamine
Allylic alkylation
Carbohydrates represent excellent tools as chiral auxiliaries, re-
agents, organocatalysts and ligands for asymmetric synthesis,1 as
they can be easily functionalized to provide efficient ligands, which
are applicable in a large number of catalytic asymmetric reactions.2
OPiv
O
O
O
Ph
O
PivO
O
O
N
Derivatives of the most accessible NH2-containing sugar, D-glucos-
PivO
N
Ar2PO
R
amine, have been evaluated as chiral ligands in numerous transi-
tion metal-catalyzed asymmetric catalysis based on Mn,3 Ni,4 V,5
Cu,6 Zn,7 and Pd. With the exception of the few examples studied
in the Suzuki–Miyaura8 and the Mizoroki–Heck8a,9 reactions, the
most studied Pd-catalyzed reactions, applying ligands derived
from glucosamine, are the allylic substitution reactions, which
represent powerful processes for the asymmetric construction of
carbon-carbon and carbon-heteroatom bonds.10
The main results in the Pd-catalyzed asymmetric allylations
with glucosamine-based ligands are those obtained from
diphenylphosphinoaryloxazoline 1,11 phosphinite-oxazoline 2,12
phosphite-oxazoline 3,13 and the phosphite-phosphoramidite 414
(Fig. 1). These ligands provide products of high enantioselectivities
(up to 98%) in the allylic alkylation of 1,3-symmetrically disubsti-
tuted acetates. A conceptually simpler and more readily available
ligand is represented by the phosphine-amide ligands 5 (Fig. 1),
which was introduced by us in 2003.15 Whereas high enantioselec-
tivities can also be obtained with this ligand, they are nevertheless
2
Ph2P
1
O
O
O
Ph
R2
O
Ph
R1
O
O
O
OMe
R1
R1
N
O
O
HN
P
O
P
O
P
O
O
O
R2
O
R3
R2
R2
R1
R1
3
R3
R2
OAc
O
R2
4
AcO
OR
O
5aα, R = α-Ac
5aβ, R = β-Ac
5bα, R = α-Me
5bβ, R = β-Me
5cα, R = α-Bn
5cβ, R = β-Bn
AcO HN
PPh2
Figure 1. Ligands based on D-glucosamine used in allylic alkylation.
* Corresponding authors. Tel.: +45 894 239 32; fax: +45 861 961 99 (T.S); tel.: +33
472 446 263; fax: +33 472 448 160 (E.F).
E-mail addresses: ts@chem.au.dk (T. Skrydstrup), framery@univ-lyon1.fr
(E. Framery).
strongly dependent on the C1-alkoxy group and on the anomeric
configuration. In order to further probe this class of ligands, these
0040-4039/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2008.09.039

6636
K. Glegoła et al. / Tetrahedron Letters 49 (2008) 6635–6638
monosaccharide phosphines were extended to their disaccharide
derivatives, as illustrated in Figure 2.16,17 Of the three classes of
disaccharide ligands prepared, the phosphine-imine derivatives 7
rather than the amide 6 or the amines 8 exhibited the highest
ee’s attaining 99% for the allylic alkylation of racemic (E)-1,3-
diphenyl-2-propenyl acetate with various nucleophiles. This came
as a surprise as (1) phosphine imine ligands are generally not good
ligands for these types of palladium-catalyzed reactions as exam-
ined with other NH2-containing sugars18 and (2) our previous
study with ligand 5 showed that it was superior to its correspond-
ing imine-phosphine and amine-phosphine. Suspecting that the
role of the reducing sugar of these disaccharide ligands for the
good enantioselectivities observed is simple sterical bulk, we have
prepared a series of simpler ligands based on 2-amino-2-deoxyglu-
cosides with varying degrees of sterical bulk at the anomeric center
and have investigated their activities in asymmetric allylic alkyl-
ations of racemic (E)-1,3-diphenyl-2-propenyl acetate with
dimethyl malonate. The results of this study are communicated
in this Letter.
PPh2
OAc
O
OAc
O
O
AcO
OR
AcO
OR
MgSO4
Toluene
AcO
NH2
AcO
N
PPh2
9a R = Ac
9b R = Me
9c R = tBu
9d R = Cy
9e R = Bn
10a R = Ac 85%
10b R = Me 75%
10c R = tBu 63%
10d R = Cy 77%
10e R = Bn 31%
OAc
O
NaBH3CN
AcO
OR
AcOH , MeOH
AcO HN
PPh2
11a R = Ac 99%
11b R = Me 99%
The functionalization of the amino group on the D-glucosamine
derivatives provided an easy access to various phosphine-imine
ligands,19 as well as to two phosphine-amine ligands20 based on the
carbohydrate moiety (Scheme 1). The condensation of 2-(diphenyl-
phosphino)-benzaldehyde onto 1,3,4,6-tetra-O-acetyl-2-amino-2-
Scheme 1. Preparation of phosphine-imine and phosphine-amine ligands 10 and
11.
12 (Scheme 2). The treatment of the D-glucosamine by a large ex-
deoxy-b-
2-deoxy-b-
D
-glucopyranose 9a or alkyl 3,4,6-tri-O-acetyl-2-amino-
-glucopyranosides 9b–e using MgSO4 as the drying
cess of acetyl bromide gave the compound 12 in 80% yield. Then,
the derivative 12 and pyridine (1.2 equiv) were dissolved in the
corresponding alcohol (ROH) to give after a stirring at 45 °C for
the desired time, the corresponding alkyl glycosides 9c–e with
yields in the range of 31–47%.
D
agent in toluene furnished the corresponding phosphine-imine
derivatives 10 with yields in the range of 63–85%, except from
benzyl 3,4,6-tri-O-acetyl-2-amino-2-deoxy-b-D-glucopyranoside
9e where a yield of 31% was obtained after purification. The reduc-
tion of the imino group of the derivatives 10a and 10b, using
NaBH3CN in a mixture of acetic acid and methanol, provided the
phosphine-amine ligands 11a and 11b in quantitative yield.
The starting materials 9 were easily generated from the com-
The phosphine-imine and phosphine-amine ligands 10 and 11
were examined in the palladium-catalyzed asymmetric allylic
alkylation of racemic (E)-1,3-diphenyl-2-propenyl acetate with di-
methyl malonate (Table 1). The reactions were performed in THF
(0.125 M) at 25 or 60 °C for 24 h, using 2 mol % of [(g
3-C3H5)PdCl]2,
mercially available
acetyl-2-amino-2-deoxy-b-
D
-glucosamine hydrochloride. 1,3,4,6-Tetra-O-
-glucopyranose 9a was obtained in
4 or 8 mol % of the sugar ligand, 3 equiv of dimethyl malonate, and
a mixture of N,O-bis(trimethylsilyl)acetamide (BSA) (3 equiv) and
KOAc (2 mol %) as the base.24 The results were compared to those
obtained previously using the phosphine-amide, phosphine-imine,
and phosphine-amine ligands 5–8.
We first examined the results obtained using phosphine-imine
derivatives 10a–e as ligands. In the case of a Pd/L ratio of 1/1, after
24 h at 25 °C, the nature of the substituent at the b-anomeric posi-
tion of the carbohydrate moiety of the ligand had no influence on
the reactivity as complete conversion and high yield (97–99%) of
the allylic product was obtained. On the other hand, this substitu-
ent greatly influenced the enantioselectivity with enantiomeric ex-
cesses produced in the range of 38–87% (Table 1, entries 1, 3, 5, 7
and 9). The use of ligands 10c or 10e, carrying a t-butoxy or benzyl-
oxy group (Table 1, entries 5 and 9), afforded high ee’s (87% or 82%,
D
three steps according to the literature procedure:21 protection of
the NH2 group with p-anisaldehyde, acetylation of the OH group,
removal of the p-methoxybenzylidene group with HCl, and a basic
washing to give the free amino group. The other glycosides 9b–e
were prepared following the process described by Billing and Nils-
son22 in the case of the methyl glycoside 9b from 3,4,6-tri-O-acet-
yl-2-amino-2-deoxy-
a-D
-glucopyranosyl bromide hydrobromide
OR
BnO
O
OBn
OR
O
BnO
O
OBn
OMe
RO
RO
OMe
O
O
RO
RO
NH
O
OBn
O
N
X
OAc
Ph2P
Ph2P
O
AcBr
(ref 22)
6 , R = Ac or H
D-Glucosamine . HCl
AcO
Br
NH2
12, 80%
OR
7 , R = Ac or H
AcO
BnO
O
OBn
OMe
X = OBn or H
O
OAc
O
RO
RO
O
ROH
AcO
NH
OR
X
Py , 45°C
9b, R = Me 75% (ref. 22)
9c, R = tBu 47% (8h)
9d, R = Cy 31% (6h)
9e, R = Bn 45% (18h)
AcO
NH2
Ph2P
8 , R = Ac or H
X = OBn or H
Figure 2. Ligands based on disaccharides with one
D
-glucosamine unit used in
allylic alkylation.
Scheme 2. Preparation of alkyl glycosides 9b–e.

K. Glegoła et al. / Tetrahedron Letters 49 (2008) 6635–6638
6637
Table 1
These results were compared with those obtained previously
from phosphine-amide ligands 5 and 6, phosphine-imine ligands
7, and phosphine-amine ligands 8. In the case of the phosphine-
Palladium-catalyzed asymmetric allylic alkylation of racemic 1,3-diphenylprop-2-
enyl acetate with dimethyl malonatea
amide ligand 515 composed of a
D-glucosamine unit, the group at
[ Pd ] (4 mol%)
Base (3 eq)
CH(CO2Me)2
Ph
OAc
CO2Me
the anomeric position has a notable influence on the activity and
selectivity of the allylic substitution. For this type of ligand, it
was necessary to have an acetoxy group at the anomeric center
in a b-orientation to observe a total conversion and an enantio-
selectivity of 83% in favor of the (R)-enantiomer, using dimethyl
malonate as nucleophile. On the other hand, with the phosphine-
imine ligands 10, a higher enantioselectivity (87% in favor of the
(S)-enantiomer) was observed when ligand 10c was applied,
possessing a bulky t-butyl group at C1 in the b-position of the
monosaccharide unit. Under the same conditions, the ligand 10a
with a b-acetoxy group instead at the anomeric carbon only
provided an e.e. of 38% in favor of the (R)-enantiomer, suggesting
+
Ph
Ph
Ph
THF (0.125 M)
CO2Me
(3 eq)
(
)
Entry
Ligand
Pd/L
Temp. (°C)
Conv.b (yieldc) (%)
eed (%) Config.e
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
10a
10a
10b
10b
10c
10c
10d
10d
10e
10e
10e
11a
11a
11b
11b
1/1
1/2
1/1
1/2
1/1
1/2
1/1
1/2
1/1
1/2
½
25
25
25
25
25
25
25
25
25
25
60
25
25
25
25
100 (99)
100 (97)
100 (98)
100 (98)
100 (98)
42 (40)
100 (97)
100 (98)
100 (97)
42 (38)
100 (97)
100 (98)
100 (98)
100 (95)
100 (96)
38 (R)
30 (R)
56 (S)
56 (S)
87 (S)
58 (S)
65 (S)
63 (S)
82 (S)
66 (S)
60 (S)
32 (S)
19 (S)
71 (S)
61 (S)
that in the case of the phosphine-imine ligands based on D-gluco-
samine, it is important to have a bulky C1–O substituent such as a
tert-butyl group. The more flexible, phosphine-amine ligand as
represented by 11b also provided interesting enantioselectivities,
Though further work is required to investigate whether increasing
the sterical bulk at C1 will further enhance the ee’s of this allylic
alkylation using this class of ligands.
In conclusion, a new and simple class of chiral phosphine-imine
and phosphine amine ligands derived from D-glucosamine were
easily prepared, and examined in the palladium-catalyzed asym-
metric allylic alkylation of racemic (E)-1,3-diphenyl-2-propenyl
acetate with dimethyl malonate. Good enantioselectivities attain-
ing 87% ee and high conversions were observed with the phos-
1/1
½
1/1
½
a
[substrate]/[CH2(CO2Me)2]/[Base]/[Pd]/[Ligand] = 25/75/75/1/1 or 25/75/75/1/
2.
b
c
Conversion determined by GC analysis.
Isolated pure product after column chromatography.
Enantiomeric excess determined by HPLC analysis (column Chiralpak AD
d
0.46 ꢀ 25 cm).
e
The absolute configuration was determined by comparison with an authentic
sample (Ref. 24).
phine-imine ligands bearing
a large substituent at the C1
position of the amino sugar. It seems that the size of the group
at the b-anomeric position of the monosaccharide 10 has a marked
influence on the enantioselectivity, thereby confirming that the
reducing sugar of the disaccharide ligands function as a sterically
demanding group. Further investigations are now underway to
optimize these two ligands in order to provide alternative means
for effective asymmetric allylic alkylations from derivatives of a
simple and abundant sugar.
respectively), suggesting that the addition of a bulky group at the
b-anomeric position of the monosaccharide has a favorable effect
on the asymmetric induction as seen in the case of the disaccharide
ligands. In the case of a Pd/L ratio of 1/2, total conversion was ob-
served after 24 h at 25 °C, with yields of 97% and 98% when ligands
10a, 10b, and 10d were applied (Table 1, entries 2, 4, and 8). From
ligands 10c and 10e (Table 1, entries 6 and 10), a low conversion of
42% was determined under the same conditions, and for the ligand
10e (Table 1, entry 11), it was necessary to perform the allylic
alkylation at 60 °C for 24 h to obtain a complete consumption of
the starting material conversion. Concerning the enantioselectivi-
ty, comparing the results obtained in the case of a Pd/L ratio of
1/1, no change was observed for the ligands 10a, 10b, and 10d,
with ee’s in the range of 30–63% (Table 1, entries 2, 4, and 8).
And when the derivatives 10c and 10e were employed as ligands,
lower enantioselectivities were noted with a loss of 29% and
16–22%, respectively (Table 1, entries 6, 10 and 11).
Acknowledgments
We are deeply appreciative of generous financial support from
the Danish National Research Foundation, the Lundbeck Founda-
tion, the Carlsberg Foundation, and the University of Aarhus. K.G.
thanks the MENSR for a fellowship.
Supplementary data
In a second study, we investigated the same allylic alkylation
reaction using phosphine-amine derivatives 11a and 11b as ligand,
where the reactions were performed under the same conditions as
described for the phosphine-imine ligands 10. Of the two ligands
tested, a total conversion with high yield (95–98%) was observed
in the case of both Pd/L ratios of 1/1 and of 1/2 after 24 h at
25 °C (Table 1, entries 12–15). Here, the enantiomeric excess ob-
served was strongly dependent on the choice of the ligand. In the
case of ligand 11a carrying an acetoxy group at the b-anomeric po-
sition of the carbohydrate unit and with Pd/L ratios of 1/1 and 1/2,
low enantioselectivities were observed: 32% and 19%, respectively
(Table 1, entries 12 and 13). More encouraging were the results ob-
tained with the ligand 11b carrying a methoxy group at the b-ano-
meric position of the carbohydrate moiety. In these cases, higher
enantiomeric excesses were obtained: 71% for a Pd/L ratio of 1/1,
and 61% for a Pd/L ratio of 1/2 (Table 1, entries 14 and 15), which
are slightly higher than those obtained for the corresponding imine
derivative 10b (entries 3 and 4).
Supplementary data (experimental details for all compounds)
associated with this article can be found, in the online version, at
doi:10.1016/j.tetlet.2008.09.039.
References and notes
1. Boysen, M. M. K. Chem. Eur. J. 2007, 13, 8648–8659.
2. (a) Dieguez, M.; Pamies, O.; Claver, C. Chem. Rev. 2004, 104, 3189–3215; (b)
Dieguez, M.; Pamies, O.; Ruiz, A.; Diaz, Y.; Castillon, S.; Claver, C. Coord. Chem.
Rev. 2004, 248, 2165–2192; (c) Dieguez, M.; Claver, C.; Pamies, O. Eur. J. Org.
Chem. 2007, 4621–4634.
3. Borriello, C.; Del Litto, R.; Panunzi, A.; Ruffo, F. Tetrahedron: Asymmetry 2004,
15, 681–686.
4. Park, H.; RajanBabu, T. V. J. Am. Chem. Soc. 2002, 124, 734–735.
5. Cucciolito, M. E.; Del Litto, R.; Roviello, G.; Ruffo, F. J. Mol. Catal. A: Chem. 2005,
236, 176–181.
6. (a) Mata, Y.; Dieguez, M.; Pamies, O.; Biswas, K.; Woodward, S. Tetrahedron:
Asymmetry 2007, 18, 1613–1617; (b) Irmak, M.; Lehnert, T.; Boysen, M. M. K.
Tetrahedron Lett. 2007, 48, 7890–7893; (c) Irmak, M.; Groschner, A.; Boysen, M.
M. K. Chem. Commun. 2007, 177–179.

6638
K. Glegoła et al. / Tetrahedron Letters 49 (2008) 6635–6638
7. (a) Bauer, T.; Tarasiuk, J.; Pasnicek, K. Tetrahedron: Asymmetry 2002, 13, 77–82;
(b) Emmerson, D. P. G.; Villard, R.; Mugnaini, C.; Batsanov, A.; Howard, J. A. K.;
Hems, W. P.; Tooze, R. P.; Davis, B. G. Org. Biomol. Chem. 2003, 1, 3826–3838; (c)
Emmerson, D. P. G.; Hems, W. P.; Davis, B. G. Tetrahedron: Asymmetry 2005, 16,
213–221; (d) Emmerson, D. P. G.; Hems, W. P.; Davis, B. G. Org. Lett. 2006, 8,
207–210.
139.1 (d, J = 18.6 Hz), 137.8 (d, J = 21.9 Hz), 136.3 (d, J = 5.0 Hz), 136.2 (d, J = 5.6
Hz), 134.0 (d, J = 3.7 Hz), 133.9, 133.6 (d, J = 6.2 Hz), 131.1, 129.3, 128.9 (d,
J = 5.6 Hz), 128.7 (d, J = 10.4 Hz), 128.6 (d, J = 3.7 Hz), 127.9 (d, J = 5.0 Hz), 92.9,
73.0, 72.6, 72.5, 67.9, 61.6, 20.8, 20.7, 20.6, 20.3; 31P NMR (121 MHz, CDCl3,
298 K): d ꢂ15.7. Anal. Calcd for C33H34NO9P: C, 63.97; H, 5.53. Found: C, 63.88;
H, 5.48.
8. (a) Beller, M.; Krauter, J. G. E.; Zapf, A. Angew. Chem., Int. Ed. 1997, 36, 772–774;
(b) Kolodziuk, R.; Penciu, A.; Tollabi, M.; Framery, E.; Goux-Henry, C.;
Iourtchenko, A.; Sinou, D. J. Organomet. Chem. 2003, 687, 384–391; (c)
Konovets, A.; Penciu, A.; Framery, E.; Percina, N.; Goux-Henry, C.; Sinou, D.
Tetrahedron Lett. 2005, 46, 3205–3208.
9. (a) Yonehara, K.; Mori, K.; Hashizume, T.; Chung, K.-G.; Ohe, K.; Uemura, S. J.
Organomet. Chem. 2000, 603, 40–49; (b) Mata, Y.; Dieguez, M.; Pamies, O.;
Claver, C. Org. Lett. 2005, 7, 5597–5599; (c) Mata, Y.; Pamies, O.; Dieguez, M.
Chem. Eur. J. 2007, 13, 3296–3304.
10. (a) Tsuji, J. In Palladium Reagents and Catalysis. Innovations in Organic Synthesis;
Wiley-VCH: New York, 1995; (b) Trost, B. M.; Van Vranken, D. L. Chem.
Rev 1996, 96, 395–422; (c) Johannsen, M.; Jorgensen, K. A. Chem. Rev. 1998,
98, 1689–1708; (d) Pfaltz, A.; Lautens, M. In Comprehensive Asymmetric
Catalysis; Jacobsen, E. N., Pfaltz, A., Yamamoto, H., Eds.; Springer: Berlin,
1999; Vol. 2,. Chapter 24 (e) Trost, B. M.; Crawley, M. L. Chem. Rev. 2003, 103,
2921–2943.
20. General procedure for the synthesis of phosphine-amine ligands 11: The
phosphine-imine derivative 10 (86
methanol (2.5 mL) and acetic acid (0.25 mL). NaBH3CN (42 mg, 650
l
mol) was dissolved in
a
mixture of
mol) was
l
added to the previous solution, and the mixture was stirred at room
temperature for 15 min before adding water (50 mL) in order to stop the
reaction. The aqueous phase was extracted with CH2Cl2 (3 ꢀ 50 mL), and the
combined organic phase was washed with a saturated solution of NaHCO3 and
then of brine, dried with Na2SO4, and concentrated. The phosphine-amine
compound 11 was obtained in quantitative yield without further purification.
Data for ligand 11a: white solid; Rf (CH2Cl2/MeOH, 30:1) = 0.63; ½a D25
ꢁ
+20.2 (c
1.0, CHCl3); 1H NMR (300 MHz, CDCl3, 298 K): d 7.41 (ddd, J = 7.7, 4.5, 1.0 Hz,
1H), 7.35–7.30 (m, 7H), 7.23–7.11 (m, 5H), 6.82 (ddd, J = 7.6, 4.5, 1.2 Hz, 1H),
5.53 (d, J = 8.6 Hz, 1H), 5.09 (dd, J = 9.2, 9.0 Hz, 1H), 5.05 (dd, J = 9.6, 9.2 Hz, 1H),
4.29 (dd, J = 12.5, 4.5 Hz, 1H), 4.05 (dd, J = 12.4, 1.9 Hz), 4.01 (br s, 2H), 3.75
(ddd, J = 9.6, 4.5, 1.9 Hz, 1H), 2.94 (dd, J = 9.0, 8.6 Hz, 1H), 2.10 (s, 3H), 2.09 (s,
3H), 2.04 (s, 3H), 2.02 (s, 3H); 13C NMR (75 MHz, CDCl3, 298 K): d 171.2, 171.1,
170.0, 169.6, 144.6 (d, J = 23.6 Hz) 136.8 (d, J = 9.9 Hz), 136.7 (d, J = 9.8 Hz),
135.5 (d, J = 13.7 Hz), 134.3 (d, J = 4.4 Hz), 134.0 (d, J = 4.9 Hz), 133.8, 129.5,
129.2 (d, J = 6.0 Hz), 129.1 (d, J = 6.6 Hz), 127.8, 95.4, 74.2, 72.8, 68.7, 62.1, 61.2,
50.8 (d, J = 23.6), 21.1, 21.0, 20.7, 20.5; 31P NMR (121 MHz, CDCl3, 298 K): d
ꢂ14.9; HRMS (ESI): m/z calcd for C33H36NO9PNa [M+Na]+ 644.2025, found
644.2032.
11. Glaser, B.; Kunz, H. Synlett 1998, 53–55.
12. (a) Yonehara, K.; Hashizume, T.; Mori, K.; Ohe, K.; Uemura, S. Chem. Commun.
1999, 415–416; (b) Yonehara, K.; Hashizume, T.; Mori, K.; Ohe, K.; Uemura, S. J.
Org. Chem. 1999, 64, 9374–9380; (c) Hashizume, T.; Yonehara, K.; Ohe, K.;
Uemura, S. J. Org. Chem. 2000, 65, 5197–5201.
13. Mata, Y.; Dieguez, M.; Pamies, O.; Claver, C. Adv. Synth. Catal. 2005, 347, 1943–
1947.
21. Myszka, H.; Bednarczyk, D.; Najder, M.; Kaca, W. Carbohydr. Res. 2003, 338,
133–141.
14. Mata, Y.; Claver, C.; Dieguez, M.; Pamies, O. Tetrahedron: Asymmetry 2006, 17,
3282–3287.
22. Billing, J. F.; Nilsson, U. J. Tetrahedron 2005, 61, 863–874.
15. (a) Tollabi, M.; Framery, E.; Goux-Henry, C.; Sinou, D. Tetrahedron: Asymmetry
2003, 14, 3329–3333; (b) Glegola, K.; Framery, E.; Goux-Henry, C.;
Pietrusiewicz, K. M.; Sinou, D. Tetrahedron 2007, 63, 7133–7141.
16. Johannesen, S. A.; Petersen, B. O.; Duus, J. O.; Skrydstrup, T. Inorg. Chem. 2007,
46, 4326–4335.
23. General procedure for the allylic alkylation: In a Schlenk tube, [(
(8.8 mg, 24 mol) and the ligand (48 mol or 96 mol) were dissolved in THF
g
3-C3H5)PdCl]2
l
l
l
(1 mL). After being stirred for 1 h at 25 °C, a solution of racemic (E)-1,3-
diphenyl-2-propenyl acetate (302 mg, 1.2 mmol) and I THF (1 mL) was added.
After 30 min, this solution was transferred to
dimethyl malonate (475 mg, 3.6 mmol), BSA (732 mg, 3.6 mmol), and KOAc
(2.5 mg, 24 mol) in THF (2 mL). The reaction mixture was stirred at the
a Schlenk tube containing
17. Johannesen, S. A.; Glegola, K.; Sinou, D.; Framery, E.; Skrydstrup, T. Tetrahedron
Lett. 2007, 48, 3569–3573.
l
18. (a) Brunner, H.; Schönherr, M.; Zabel, M. Tetrahedron: Asymmetry 2001, 12,
2671–2675; (b) Brunner, H.; Schönherr, M.; Zabel, M. Tetrahedron: Asymmetry
2003, 14, 1115–1122; (c) Borriello, C.; Cucciolito, M. E.; Panunzi, A.; Ruffo, F.
Inorg. Chim. Acta 2003, 353, 238–244.
desired temperature for 24 h. The conversion was determined by GC analysis.
The mixture was then diluted with diethyl ether (15 mL) and water (5 mL). The
organic phase was washed brine and dried over MgSO4. Evaporation of the
solvents gave a residue, which was purified by chromatography (petroleum
ether/ethyl acetate, 10/1). The enantiomeric excess of dimethyl [(E)-1,3-
diphenyl-prop-2-en-1-yl]malonate was determined by HPLC analysis: tR
18 min for (R)-isomer and tS 24 min for (S)-isomer. The absolute
configuration of the enantiomers was determined by comparison of the
retention times with that of an authentic sample23 and by measurement of the
optical rotation of the product. Colorless oil; Rf (Et2O/EtOAc, 10:1) = 0.40; 1H
NMR (300 MHz, CDCl3, 298 K): d 7.28–7.20 (m, 10H), 6.50 (d, J = 15.6 Hz, 1H),
6.34 (dd, J = 15.6, 8.5 Hz, 1H), 4.29 (dd, J = 10.9, 8.5 Hz, 1H), 3.95 (d, J = 10.9 Hz,
1H), 3.72 (s, 3H), 3.53 (s, 3H). The 1H NMR spectrum is in agreement with the
literature (see Ref. 25).
19. General procedure for the synthesis of phosphine-imine ligands 10: The gluco-
pyranoside derivative
9 (0.35 mmol), 2-diphenylphosphinobenzaldehyde
(102 mg, 0.35 mmol) and toluene (5 mL) were added to dried MgSO4 under
an inert atmosphere. The reactional mixture was stirred at 60 °C for 12 h. After
concentration, the residue was purified by flash chromatography to give
phosphine-imine derivatives 10. Data for ligand 10a: Pale yellow solid (yield
85%); Rf (CH2Cl2/MeOH, 30:1) = 0.70; ½ ꢁ
a 2D5 +25.8 (c 1.0, CHCl3); 1H NMR
(300 MHz, CDCl3, 298 K): d 9.04 (d, J = 4.9 Hz, 1H), 7.95 (dd, J = 6.8, 4.0 Hz, 1H),
7.42–7.15 (m, 12H); 6.94–6.90 (m, 1H), 5.85 (d, J = 8.4 Hz, 1H), 5.36 (dd, J = 9.4,
9.4 Hz, 1H), 5.10 (dd, J = 10.2, 9.4 Hz, 1H), 4.35 (dd, J = 12.4, 4.5 Hz, 1H), 4.13
(dd, J = 12.1, 1.9 Hz, 1H), 3.93 (ddd, J = 10.2, 4.5, 1.9 Hz, 1H), 3.46 (dd, J = 9.4,
8.4 Hz, 1H), 2.08 (s, 3H), 2.01 (s, 3H), 1.83 (s, 3H), 1.70 (s, 3H); 13C NMR
(75 MHz, CDCl3, 298 K): d 170.7, 169.8, 169.7, 168.8, 163.8 (d, J = 25.4 Hz),
24. Sprinz, J.; Helmchen, G. Tetrahedron Lett. 1993, 34, 1769–1772.
25. Vyskocil, S.; Smrcina, M.; Hanus, V.; Polasek, M.; Kocovsky, P. J. Org. Chem.
1998, 63, 7738–7748.